ascension: src/text.c@7cf310cc47cb

     1 /*

     2  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

     3  * Copyright 2023 Mike Becker. All rights reserved.

     4  *

     5  * Redistribution and use in source and binary forms, with or without

     6  * modification, are permitted provided that the following conditions are met:

     7  *

     8  *   1. Redistributions of source code must retain the above copyright

     9  *      notice, this list of conditions and the following disclaimer.

    10  *

    11  *   2. Redistributions in binary form must reproduce the above copyright

    12  *      notice, this list of conditions and the following disclaimer in the

    13  *      documentation and/or other materials provided with the distribution.

    14  *

    15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

    16  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

    17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

    18  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE

    19  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

    20  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

    21  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

    22  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

    23  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

    24  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

    25  * POSSIBILITY OF SUCH DAMAGE.

    26  */

    28 #include "ascension/text.h"

    29 #include "ascension/context.h"

    30 #include "ascension/error.h"

    31 #include "ascension/shader.h"

    33 #include <GL/glew.h>

    35 static void asc_text_draw(AscText const *node) {

    36     if (node->color.alpha == 0 || node->hidden || node->tex_id == 0) {

    37         return;

    38     }

    40     // Upload model matrix

    41     glUniformMatrix4fv(ASC_SHADER_FONT.base.model, 1,

    42                        GL_FALSE, node->base.final_transform);

    44     // Upload surface

    45     glActiveTexture(GL_TEXTURE0);

    46     glBindTexture(GL_TEXTURE_RECTANGLE, node->tex_id);

    47     glUniform1i(ASC_SHADER_FONT.surface, 0);

    49     // Draw mesh

    50     asc_primitives_draw_plane();

    51 }

    53 static void asc_text_update_transform(AscText *node) {

    54     asc_transform_scale2i(node->base.local_transform, node->dimension);

    55     asc_transform_translate2i(node->base.world_transform, node->position);

    56 }

    58 static void asc_text_update(AscText *node) {

    59     // short circuit if fully transparent or hidden, we don't need anything

    60     if (node->color.alpha == 0 || node->hidden) {

    61         return;

    62     }

    64     // Generate new texture, if required

    65     if (node->tex_id == 0) {

    66         glGenTextures(1, &node->tex_id);

    67         glBindTexture(GL_TEXTURE_RECTANGLE, node->tex_id);

    68         glTexParameteri(GL_TEXTURE_RECTANGLE, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

    69         glTexParameteri(GL_TEXTURE_RECTANGLE, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    70         asc_dprintf("Generated new texture for text node: %u", node->tex_id);

    71     }

    73     // Render text onto a surface

    74     SDL_Surface *surface = TTF_RenderUTF8_Blended_Wrapped(

    75             asc_font_cache_validate(node->font)->ptr,

    76             node->text,

    77             asc_col_sdl(node->color),

    78             node->max_width

    79     );

    80     if (surface == NULL) {

    81         asc_error(SDL_GetError());

    82         return;

    83     }

    84     node->dimension.width = surface->w;

    85     node->dimension.height = surface->h;

    86     asc_node_update_transform(node);

    88     // Transfer Image Data

    89     // TODO: move the image data transfer to a separate function - we will need it more often

    90     glBindTexture(GL_TEXTURE_RECTANGLE, node->tex_id);

    91     glPixelStorei(GL_UNPACK_ROW_LENGTH, surface->pitch / surface->format->BytesPerPixel);

    92     glTexImage2D(GL_TEXTURE_RECTANGLE, 0, GL_RGBA,

    93                  surface->w, surface->h,

    94                  0, GL_BGRA, GL_UNSIGNED_BYTE, surface->pixels);

    96     // Free the surface

    97     SDL_FreeSurface(surface);

    98 }

   100 AscSceneNode *asc_text(int x, int y, char const *text) {

   101     AscText *node = calloc(1, sizeof(AscText));

   102     if (node == NULL) {

   103         asc_error("Out of memory.");

   104         return NULL;

   105     }

   107     node->base.render_group = ASC_RENDER_GROUP_FONTS;

   108     node->base.free_func = (asc_scene_free_func) asc_text_free;

   109     node->base.update_func = (asc_scene_update_func) asc_text_update;

   110     node->base.transform_update_func = (asc_scene_update_func) asc_text_update_transform;

   111     node->base.draw_func = (asc_scene_draw_func) asc_text_draw;

   113     node->position.x = x;

   114     node->position.y = y;

   115     node->font = asc_context.active_font;

   116     node->color = asc_context.ink;

   117     if (text != NULL) {

   118         node->text = strdup(text);

   119     }

   121     // initialize

   122     asc_text_update(node);

   123     asc_text_update_transform(node);

   125     return &node->base;

   126 }

   128 void asc_text_free(AscText *node) {

   129     asc_dprintf("Release text node texture: %u", node->tex_id);

   130     glDeleteTextures(1, &node->tex_id);

   131     free(node->text);

   132     free(node);

   133 }

Mercurial > hg > ascension / file revision