Text.cpp

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/* Copyright (c) 2012-2017, ARM Limited and Contributors
 *
 * SPDX-License-Identifier: MIT
 *
 * Permission is hereby granted, free of charge,
 * to any person obtaining a copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#include "Common.h"
#include "Text.h"
#include "Texture.h"
#include "Shader.h"
#include "VectorTypes.h"

#include <cstring>

namespace MaliSDK
{ 
    const float Text::scale = 2.0f;

    const int Text::textureCharacterWidth  = 8;
    const int Text::textureCharacterHeight = 16;

    Text::Text(const char* vertexShaderFileName,
               const char* fragmentShaderFileName,
               const char* textureFileName,
               int         windowWidth,
               int         windowHeight)
    {
        vertexShaderID   = 0;
        fragmentShaderID = 0;
        programID        = 0;

        numberOfCharacters     = 0;
        textVertex             = NULL;
        textTextureCoordinates = NULL;
        color                  = NULL;
        textIndex              = NULL;

        /* Create an orthographic projection. */
        projectionMatrix = Matrix::matrixOrthographic(0, (float)windowWidth, 0, (float)windowHeight, 0, 1);

        /* Shaders. */
        Shader::processShader(&vertexShaderID,   vertexShaderFileName,   GL_VERTEX_SHADER);
        Shader::processShader(&fragmentShaderID, fragmentShaderFileName, GL_FRAGMENT_SHADER);

        /* Set up shaders. */
        programID = GL_CHECK(glCreateProgram());

        GL_CHECK(glAttachShader(programID, vertexShaderID));
        GL_CHECK(glAttachShader(programID, fragmentShaderID));
        GL_CHECK(glLinkProgram(programID));
        GL_CHECK(glUseProgram(programID));

        /* Vertex positions. */
        m_iLocPosition = GL_CHECK(glGetAttribLocation(programID, "a_v4Position"));
        /* Text colors. */
        m_iLocTextColor = GL_CHECK(glGetAttribLocation(programID, "a_v4FontColor"));
        /* TexCoords. */
        m_iLocTexCoord = GL_CHECK(glGetAttribLocation(programID, "a_v2TexCoord"));
        /* Projection matrix. */
        m_iLocProjection = GL_CHECK(glGetUniformLocation(programID, "u_m4Projection"));
        /* Set the sampler to point at the 0th texture unit. */
        m_iLocTexture = GL_CHECK(glGetUniformLocation(programID, "u_s2dTexture"));

        ASSERT(m_iLocPosition != -1,  "Attribute not found: a_v4Position");
        ASSERT(m_iLocTextColor != -1, "Attribute not found: a_v4FontColor");
        ASSERT(m_iLocTexCoord != -1, "Attribute not found: a_v2TexCoord");
        ASSERT(m_iLocProjection != -1, "Uniform not found: u_m4Projection");
        ASSERT(m_iLocTexture != -1, "Uniform not found: u_s2dTexture");

        GL_CHECK(glUniformMatrix4fv(m_iLocProjection, 1, GL_FALSE, projectionMatrix.getAsArray()));
        GL_CHECK(glUniform1i       (m_iLocTexture, 1));

        /* Load texture. */
        GL_CHECK(glActiveTexture(GL_TEXTURE1));
        GL_CHECK(glGenTextures  (1, &textureID));
        GL_CHECK(glBindTexture  (GL_TEXTURE_2D, textureID));

        /* Set filtering. */
        GL_CHECK(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR));
        GL_CHECK(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR));
        GL_CHECK(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE));
        GL_CHECK(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE));

        unsigned char *textureData = NULL;

        Texture::loadData(textureFileName, &textureData);

        GL_CHECK(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 256, 48, 0, GL_RGBA, GL_UNSIGNED_BYTE, textureData));

        free(textureData);
        textureData = NULL;
    }

    void Text::clear(void)
    {
        numberOfCharacters = 0;

        free(textVertex);
        free(textTextureCoordinates);
        free(color);
        free(textIndex);

        textVertex = NULL;
        textTextureCoordinates = NULL;
        color = NULL;
        textIndex = NULL;
    }

    void Text::addString(int xPosition, int yPosition, const char *string, int red, int green, int blue, int alpha)
    {
        int length = (int)strlen(string);
        int iTexCoordPos = 4 * 2 * numberOfCharacters;
        int iVertexPos = 4 * 3 * numberOfCharacters;
        int iColorPos = 4 * 4 * numberOfCharacters;
        int iIndex = 0;
        int iIndexPos = 0;

        numberOfCharacters += length;

        /* Realloc memory. */
        textVertex = (float *)realloc(textVertex, numberOfCharacters * 4 * 3 * sizeof(float));
        textTextureCoordinates = (float *)realloc(textTextureCoordinates, numberOfCharacters * 4 * 2 * sizeof(float));
        color = (float *)realloc(color, numberOfCharacters * 4 * 4 * sizeof(float));
        textIndex = (GLshort *)realloc(textIndex, (numberOfCharacters * 6 - 2) * sizeof(GLshort));
        if((textVertex == NULL) || (textTextureCoordinates == NULL) || (color == NULL) || (textIndex == NULL))
        {
            LOGE("Out of memory at %s:%i\n", __FILE__, __LINE__);
            exit(1);
        }

        /* Re-init entire index array. */
        textIndex[iIndex ++] = 0;
        textIndex[iIndex ++] = 1;
        textIndex[iIndex ++] = 2;
        textIndex[iIndex ++] = 3;

        iIndexPos = 4;
        for(int cIndex = 1; cIndex < numberOfCharacters; cIndex ++)
        {
            textIndex[iIndexPos ++] = iIndex - 1;
            textIndex[iIndexPos ++] = iIndex;
            textIndex[iIndexPos ++] = iIndex++;
            textIndex[iIndexPos ++] = iIndex++;
            textIndex[iIndexPos ++] = iIndex++;
            textIndex[iIndexPos ++] = iIndex++;
        }

        for(int iChar = 0; iChar < (signed int)strlen(string); iChar ++)
        {
            char cChar = string[iChar];
            int iCharX = 0;
            int iCharY = 0;
            Vec2 sBottom_left;
            Vec2 sBottom_right;
            Vec2 sTop_left;
            Vec2 sTop_right;

            /* Calculate tex coord for char here. */
            cChar -= 32;
            iCharX = cChar % 32;
            iCharY = cChar / 32;
            iCharX *= textureCharacterWidth;
            iCharY *= textureCharacterHeight;
            sBottom_left.x = iCharX;
            sBottom_left.y = iCharY;
            sBottom_right.x = iCharX + textureCharacterWidth;
            sBottom_right.y = iCharY;
            sTop_left.x = iCharX;
            sTop_left.y = iCharY + textureCharacterHeight;
            sTop_right.x = iCharX + textureCharacterWidth;
            sTop_right.y = iCharY + textureCharacterHeight;

            /* Add vertex position data here. */
            textVertex[iVertexPos++] = xPosition + iChar * textureCharacterWidth * scale;
            textVertex[iVertexPos++] = (float)yPosition;
            textVertex[iVertexPos++] = 0;

            textVertex[iVertexPos++] = xPosition + (iChar + 1) * textureCharacterWidth * scale;
            textVertex[iVertexPos++] = (float)yPosition;
            textVertex[iVertexPos++] = 0;

            textVertex[iVertexPos++] = xPosition + iChar * textureCharacterWidth * scale;
            textVertex[iVertexPos++] = yPosition + textureCharacterHeight * scale;
            textVertex[iVertexPos++] = 0;

            textVertex[iVertexPos++] = xPosition + (iChar + 1) * textureCharacterWidth * scale;
            textVertex[iVertexPos++] = yPosition + textureCharacterHeight * scale;
            textVertex[iVertexPos++] = 0;

            /* Texture coords here. Because textures are read in upside down, flip Y coords here. */
            textTextureCoordinates[iTexCoordPos++] = sBottom_left.x / 256.0f;
            textTextureCoordinates[iTexCoordPos++] = sTop_left.y / 48.0f;

            textTextureCoordinates[iTexCoordPos++] = sBottom_right.x / 256.0f;
            textTextureCoordinates[iTexCoordPos++] = sTop_right.y / 48.0f;

            textTextureCoordinates[iTexCoordPos++] = sTop_left.x / 256.0f;
            textTextureCoordinates[iTexCoordPos++] = sBottom_left.y / 48.0f;

            textTextureCoordinates[iTexCoordPos++] = sTop_right.x / 256.0f;
            textTextureCoordinates[iTexCoordPos++] = sBottom_right.y / 48.0f;

            /* Color data. */
            color[iColorPos ++] = red / 255.0f;
            color[iColorPos ++] = green / 255.0f;
            color[iColorPos ++] = blue / 255.0f;
            color[iColorPos ++] = alpha / 255.0f;

            /* Copy to the other 3 vertices. */
            memcpy(&color[iColorPos], &color[iColorPos - 4], 4 * sizeof(float));
            memcpy(&color[iColorPos + 4], &color[iColorPos], 4 * sizeof(float));
            memcpy(&color[iColorPos + 8], &color[iColorPos + 4], 4 * sizeof(float));
            iColorPos += 3 * 4;
        }
    }

    void Text::draw(void)
    {
        GL_CHECK(glBindVertexArray(0));
        GL_CHECK(glBindBuffer(GL_ARRAY_BUFFER, 0));

        if(numberOfCharacters == 0) 
        {
            return;
        }

        GL_CHECK(glUseProgram(programID));

        if(m_iLocPosition != -1)
        {
            GL_CHECK(glEnableVertexAttribArray(m_iLocPosition));
            GL_CHECK(glVertexAttribPointer(m_iLocPosition, 3, GL_FLOAT, GL_FALSE, 0, textVertex));
        }

        if(m_iLocTextColor != -1)
        {
            GL_CHECK(glEnableVertexAttribArray(m_iLocTextColor));
            GL_CHECK(glVertexAttribPointer(m_iLocTextColor, 4, GL_FLOAT, GL_FALSE, 0, color));
        }

        if(m_iLocTexCoord != -1)
        {
            GL_CHECK(glEnableVertexAttribArray(m_iLocTexCoord));
            GL_CHECK(glVertexAttribPointer(m_iLocTexCoord, 2, GL_FLOAT, GL_FALSE, 0, textTextureCoordinates));
        }

        if(m_iLocProjection != -1)
        {
            GL_CHECK(glUniformMatrix4fv(m_iLocProjection, 1, GL_FALSE, projectionMatrix.getAsArray()));
        }

        GL_CHECK(glActiveTexture(GL_TEXTURE0));
        GL_CHECK(glBindTexture(GL_TEXTURE_2D, textureID));

        GL_CHECK(glDrawElements(GL_TRIANGLE_STRIP, numberOfCharacters * 6 - 2, GL_UNSIGNED_SHORT, textIndex));

        if(m_iLocTextColor != -1)
        {
            GL_CHECK(glDisableVertexAttribArray(m_iLocTextColor));
        }

        if(m_iLocTexCoord != -1)
        {
            GL_CHECK(glDisableVertexAttribArray(m_iLocTexCoord));
        }

        if(m_iLocPosition != -1)
        {
            GL_CHECK(glDisableVertexAttribArray(m_iLocPosition));
        }
    }

    Text::~Text(void)
    {
        clear();
        
        GL_CHECK(glDeleteTextures(1, &textureID));
    }
}